Do pet shampoos contribute to autism?

A new large population-based study suggests that pet shampoos containing the class of insecticides known as pyrethrins may contribute to autism spectrum disorder (ASD). The study found that mothers of children with ASD were twice as likely to have reported using insecticides containing pyrethrins. And, the risk was greatest if the insecticide was used during the second trimester of pregnancy. That’s swell – yet another thing to feel guilty about if you have a child exhibiting ASD.

But, it is unlikely that exposure to pyrethrins is the only cause. Rather, the current theory is that autism is triggered by the interplay of genetic and environmental factors, and pyrethrins may be one of the environmental factors. But they are probably not the only one. For example, another study released earlier this week found that exposure to organophosphates during pregnancy was associated with a two-fold increased risk of developmental disorders in children. Organophosphates are also used in pet shampoos and other household products, and also for sheep dip (and can contaminate non-organic wool).

Nevertheless, laboratory animal studies have shown that pyrethrins can damage the blood-brain barrier during early life and cause neuronal damage and may also interrupt the transmission of signals along nerve fibers. Thus, the findings of this new study are consistent with prior laboratory animal studies. A researcher with the study, Isaac Pessah at University of Cal. at Davis stated that “Autism is associated with an imbalance between excitatory and inhibitory neurotransmitters within the brain, and one could hypothesize that children with an imbalance in this system may be more sensitive to the effects of pyrethrins.”

And, just for the record, pyrethrins are natural. Pyrethroids are the synethetic version of pyrethrins. Pyrethrins are a naturally occuring insecticide extracted from pyrethum flowers such as chrysanthemums. Pyrethins are used primiarily in residential insecticide products and they are often advertised as “natural.”

So what can the concerned parent do? Eliminate the use of conventional pesticides, including pet care products, around the home, especially when trying to get pregnant or when pregnant, and during a child’s early years. Read those labels when buying products! Don’t be fooled by claims of “natural” – make sure you know what you are buying. For example, I stumbled across this product on Petco’s website: Bio-Groom Flea & Tick Pyrethrin Spray. It is advertised as a “water based formula with lanolin and aloe vera.” Sounds good, right? But, it is a pyrethrin spray, and the ingredient list identifies pyrethrins as one of the active ingredients, albeit naturally derived.

Okay, I understand that fleas and of course ticks are bad news. I don’t want to live with a bunch of fleas either. But you can try some of the non-toxic solutions for pest control. My favorite is using white distilled vinegar or Dr. Bronner’s Peppermint Castile soap (mixed with some water) to prevent ant attacks.